Electrochemical cells such those found in lithium ion batteries are known to provide high energy densities and specific energies of any battery chemistry. Hence they represent promising candidates for mobile and stationary energy storage applications. However, safety problems arise in such cells from the presence of volatile organic solvents. Thus, there is a need to use inorganic, solid-state electrolytes that exhibit high conductivity to eliminate the problems caused by liquid electrolyte systems.
A number of publications, patent applications, and patents describe advances in solid electrolyte materials for lithium ion cells. However, known sodium batteries are incapable of operating at room temperature because there is no known electrolyte of a sufficiently high conductivity at room temperature for sodium ion transport.
Thus, opportunities exist to provide a sodium-conducting solid electrolyte having sufficiently high conductivity for use in a room-temperature solid-state sodium electrochemical cell.